I was called to a home to perform maintenance on a 2013 train 3 1/2 ton split heat pump up flow. Upon arrival, I found that the unit had a 25° temperature split and was cooling at 49° upon departure. I performed a thorough inspection of the unit and found that all electronics and pressure pressures were within factory specifications. I also checked the refrigerant levels and found that they were within the manufacturer's recommended range. I performed a cleaning and lubrication of the unit's components and replaced the air filter. After completing the maintenance, I tested the unit to ensure that it was operating properly. The customer was very satisfied with the work and expressed that the unit was running much more efficiently now.